1. Field of the Invention
The present disclosure generally relates to rechargeable battery systems. More particularly, the present disclosure relates to a method for estimating remaining battery capacity using an algorithm based on battery terminal voltage.
2. Description of the Related Art
In recent years there has been an explosion in the popularity and types of portable electronic devices. Such devices include communication and entertainment devices, such as cell phones, PDA's, portable music and video players and the like, as well as electronic devices that are implantable into a human or animal body, such as pacemakers, implantable drug delivery systems and nerve stimulation devices. These and other types of portable electronic devices generally rely upon electrochemical storage batteries as a power source. Many of these devices use rechargeable batteries, while others use conventional single-use batteries. In either case, however, it can be desirable to have an accurate estimate of remaining battery capacity or battery life in order to know when to recharge or replace the batteries. This is particularly true in the case of implantable electronic devices, where the health of the user may depend upon proper functioning of the device, and the device is not easily accessible, since replacing a battery requires an invasive surgical procedure.
There are various known methods for estimating remaining battery life in electronic devices that are currently used. For example, methods that have been adopted to predict or estimate remaining battery life include the remaining capacity (mAh) method, direct energy computation (J), and the coulomb counter (Amps/s) method. Unfortunately, many of these methods rely upon some significant and sometimes inaccurate assumptions, can be moderately to highly complex to implement, and the accuracy of these methods varies widely. Ironically, some battery life estimation methods that are currently used are computationally intensive, such that they impose a substantial strain on battery life in the course of computing battery life and reduce overall system efficiency.
The present disclosure is directed to overcoming, or at least reducing the effects, of one or more of the issues set forth above.